linux-toradex.git/fs, branch v4.4.94

nfsd/callback: Cleanup callback cred on shutdown

2017-10-21T15:09:06+00:00

[ Upstream commit f7d1ddbe7648af7460d23688c8c131342eb43b3a ]

The rpccred gotten from rpc_lookup_machine_cred() should be put when
state is shutdown.

Signed-off-by: Kinglong Mee 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ceph: clean up unsafe d_parent accesses in build_dentry_path

2017-10-21T15:09:06+00:00

[ Upstream commit c6b0b656ca24ede6657abb4a2cd910fa9c1879ba ]

While we hold a reference to the dentry when build_dentry_path is
called, we could end up racing with a rename that changes d_parent.
Handle that situation correctly, by using the rcu_read_lock to
ensure that the parent dentry and inode stick around long enough
to safely check ceph_snap and ceph_ino.

Link: http://tracker.ceph.com/issues/18148
Signed-off-by: Jeff Layton 
Reviewed-by: Yan, Zheng 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ocfs2/dlmglue: prepare tracking logic to avoid recursive cluster lock

2017-10-21T15:09:05+00:00

[ Upstream commit 439a36b8ef38657f765b80b775e2885338d72451 ]

We are in the situation that we have to avoid recursive cluster locking,
but there is no way to check if a cluster lock has been taken by a precess
already.

Mostly, we can avoid recursive locking by writing code carefully.
However, we found that it's very hard to handle the routines that are
invoked directly by vfs code.  For instance:

  const struct inode_operations ocfs2_file_iops = {
      .permission     = ocfs2_permission,
      .get_acl        = ocfs2_iop_get_acl,
      .set_acl        = ocfs2_iop_set_acl,
  };

Both ocfs2_permission() and ocfs2_iop_get_acl() call ocfs2_inode_lock(PR):

  do_sys_open
   may_open
    inode_permission
     ocfs2_permission
      ocfs2_inode_lock() <=== first time
       generic_permission
        get_acl
         ocfs2_iop_get_acl
  	ocfs2_inode_lock() <=== recursive one

A deadlock will occur if a remote EX request comes in between two of
ocfs2_inode_lock().  Briefly describe how the deadlock is formed:

On one hand, OCFS2_LOCK_BLOCKED flag of this lockres is set in
BAST(ocfs2_generic_handle_bast) when downconvert is started on behalf of
the remote EX lock request.  Another hand, the recursive cluster lock
(the second one) will be blocked in in __ocfs2_cluster_lock() because of
OCFS2_LOCK_BLOCKED.  But, the downconvert never complete, why? because
there is no chance for the first cluster lock on this node to be
unlocked - we block ourselves in the code path.

The idea to fix this issue is mostly taken from gfs2 code.

1. introduce a new field: struct ocfs2_lock_res.l_holders, to keep track
   of the processes' pid who has taken the cluster lock of this lock
   resource;

2. introduce a new flag for ocfs2_inode_lock_full:
   OCFS2_META_LOCK_GETBH; it means just getting back disk inode bh for
   us if we've got cluster lock.

3. export a helper: ocfs2_is_locked_by_me() is used to check if we have
   got the cluster lock in the upper code path.

The tracking logic should be used by some of the ocfs2 vfs's callbacks,
to solve the recursive locking issue cuased by the fact that vfs
routines can call into each other.

The performance penalty of processing the holder list should only be
seen at a few cases where the tracking logic is used, such as get/set
acl.

You may ask what if the first time we got a PR lock, and the second time
we want a EX lock? fortunately, this case never happens in the real
world, as far as I can see, including permission check,
(get|set)_(acl|attr), and the gfs2 code also do so.

[sfr@canb.auug.org.au remove some inlines]
Link: http://lkml.kernel.org/r/20170117100948.11657-2-zren@suse.com
Signed-off-by: Eric Ren 
Reviewed-by: Junxiao Bi 
Reviewed-by: Joseph Qi 
Cc: Stephen Rothwell 
Cc: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 

Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

f2fs: do not wait for writeback in write_begin

2017-10-21T15:09:05+00:00

[ Upstream commit 86d54795c94532075d862aa0a79f0c981dab4bdd ]

Otherwise we can get livelock like below.

[79880.428136] dbench          D    0 18405  18404 0x00000000
[79880.428139] Call Trace:
[79880.428142]  __schedule+0x219/0x6b0
[79880.428144]  schedule+0x36/0x80
[79880.428147]  schedule_timeout+0x243/0x2e0
[79880.428152]  ? update_sd_lb_stats+0x16b/0x5f0
[79880.428155]  ? ktime_get+0x3c/0xb0
[79880.428157]  io_schedule_timeout+0xa6/0x110
[79880.428161]  __lock_page+0xf7/0x130
[79880.428164]  ? unlock_page+0x30/0x30
[79880.428167]  pagecache_get_page+0x16b/0x250
[79880.428171]  grab_cache_page_write_begin+0x20/0x40
[79880.428182]  f2fs_write_begin+0xa2/0xdb0 [f2fs]
[79880.428192]  ? f2fs_mark_inode_dirty_sync+0x16/0x30 [f2fs]
[79880.428197]  ? kmem_cache_free+0x79/0x200
[79880.428203]  ? __mark_inode_dirty+0x17f/0x360
[79880.428206]  generic_perform_write+0xbb/0x190
[79880.428213]  ? file_update_time+0xa4/0xf0
[79880.428217]  __generic_file_write_iter+0x19b/0x1e0
[79880.428226]  f2fs_file_write_iter+0x9c/0x180 [f2fs]
[79880.428231]  __vfs_write+0xc5/0x140
[79880.428235]  vfs_write+0xb2/0x1b0
[79880.428238]  SyS_write+0x46/0xa0
[79880.428242]  entry_SYSCALL_64_fastpath+0x1e/0xad

Fixes: cae96a5c8ab6 ("f2fs: check io submission more precisely")
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Btrfs: send, fix failure to rename top level inode due to name collision

2017-10-21T15:09:04+00:00

[ Upstream commit 4dd9920d991745c4a16f53a8f615f706fbe4b3f7 ]

Under certain situations, an incremental send operation can fail due to a
premature attempt to create a new top level inode (a direct child of the
subvolume/snapshot root) whose name collides with another inode that was
removed from the send snapshot.

Consider the following example scenario.

Parent snapshot:

  .                 (ino 256, gen 8)
  |---- a1/         (ino 257, gen 9)
  |---- a2/         (ino 258, gen 9)

Send snapshot:

  .                 (ino 256, gen 3)
  |---- a2/         (ino 257, gen 7)

In this scenario, when receiving the incremental send stream, the btrfs
receive command fails like this (ran in verbose mode, -vv argument):

  rmdir a1
  mkfile o257-7-0
  rename o257-7-0 -> a2
  ERROR: rename o257-7-0 -> a2 failed: Is a directory

What happens when computing the incremental send stream is:

1) An operation to remove the directory with inode number 257 and
   generation 9 is issued.

2) An operation to create the inode with number 257 and generation 7 is
   issued. This creates the inode with an orphanized name of "o257-7-0".

3) An operation rename the new inode 257 to its final name, "a2", is
   issued. This is incorrect because inode 258, which has the same name
   and it's a child of the same parent (root inode 256), was not yet
   processed and therefore no rmdir operation for it was yet issued.
   The rename operation is issued because we fail to detect that the
   name of the new inode 257 collides with inode 258, because their
   parent, a subvolume/snapshot root (inode 256) has a different
   generation in both snapshots.

So fix this by ignoring the generation value of a parent directory that
matches a root inode (number 256) when we are checking if the name of the
inode currently being processed collides with the name of some other
inode that was not yet processed.

We can achieve this scenario of different inodes with the same number but
different generation values either by mounting a filesystem with the inode
cache option (-o inode_cache) or by creating and sending snapshots across
different filesystems, like in the following example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt
  $ mkdir /mnt/a1
  $ mkdir /mnt/a2
  $ btrfs subvolume snapshot -r /mnt /mnt/snap1
  $ btrfs send /mnt/snap1 -f /tmp/1.snap
  $ umount /mnt

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt
  $ touch /mnt/a2
  $ btrfs subvolume snapshot -r /mnt /mnt/snap2
  $ btrfs receive /mnt -f /tmp/1.snap
  # Take note that once the filesystem is created, its current
  # generation has value 7 so the inode from the second snapshot has
  # a generation value of 7. And after receiving the first snapshot
  # the filesystem is at a generation value of 10, because the call to
  # create the second snapshot bumps the generation to 8 (the snapshot
  # creation ioctl does a transaction commit), the receive command calls
  # the snapshot creation ioctl to create the first snapshot, which bumps
  # the filesystem's generation to 9, and finally when the receive
  # operation finishes it calls an ioctl to transition the first snapshot
  # (snap1) from RW mode to RO mode, which does another transaction commit
  # and bumps the filesystem's generation to 10.
  $ rm -f /tmp/1.snap
  $ btrfs send /mnt/snap1 -f /tmp/1.snap
  $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/2.snap
  $ umount /mnt

  $ mkfs.btrfs -f /dev/sdd
  $ mount /dev/sdd /mnt
  $ btrfs receive /mnt /tmp/1.snap
  # Receive of snapshot snap2 used to fail.
  $ btrfs receive /mnt /tmp/2.snap

Signed-off-by: Robbie Ko 
Reviewed-by: Filipe Manana 
[Rewrote changelog to be more precise and clear]
Signed-off-by: Filipe Manana 

Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

direct-io: Prevent NULL pointer access in submit_page_section

2017-10-18T07:20:42+00:00

commit 899f0429c7d3eed886406cd72182bee3b96aa1f9 upstream.

In the code added to function submit_page_section by commit b1058b981,
sdio->bio can currently be NULL when calling dio_bio_submit.  This then
leads to a NULL pointer access in dio_bio_submit, so check for a NULL
bio in submit_page_section before trying to submit it instead.

Fixes xfstest generic/250 on gfs2.

Signed-off-by: Andreas Gruenbacher 
Reviewed-by: Jan Kara 
Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

CIFS: Reconnect expired SMB sessions

2017-10-18T07:20:40+00:00

commit 511c54a2f69195b28afb9dd119f03787b1625bb4 upstream.

According to the MS-SMB2 spec (3.2.5.1.6) once the client receives
STATUS_NETWORK_SESSION_EXPIRED error code from a server it should
reconnect the current SMB session. Currently the client doesn't do
that. This can result in subsequent client requests failing by
the server. The patch adds an additional logic to the demultiplex
thread to identify expired sessions and reconnect them.

Signed-off-by: Pavel Shilovsky 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

ext4: in ext4_seek_{hole,data}, return -ENXIO for negative offsets

2017-10-18T07:20:40+00:00

commit 1bd8d6cd3e413d64e543ec3e69ff43e75a1cf1ea upstream.

In the ext4 implementations of SEEK_HOLE and SEEK_DATA, make sure we
return -ENXIO for negative offsets instead of banging around inside
the extent code and returning -EFSCORRUPTED.

Reported-by: Mateusz S 
Signed-off-by: Darrick J. Wong 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: don't allow encrypted operations without keys

2017-10-12T09:27:35+00:00

commit 173b8439e1ba362007315868928bf9d26e5cc5a6 upstream.

While we allow deletes without the key, the following should not be
permitted:

# cd /vdc/encrypted-dir-without-key
# ls -l
total 4
-rw-r--r-- 1 root root   0 Dec 27 22:35 6,LKNRJsp209FbXoSvJWzB
-rw-r--r-- 1 root root 286 Dec 27 22:35 uRJ5vJh9gE7vcomYMqTAyD
# mv uRJ5vJh9gE7vcomYMqTAyD  6,LKNRJsp209FbXoSvJWzB

Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: Don't clear SGID when inheriting ACLs

2017-10-12T09:27:35+00:00

commit a3bb2d5587521eea6dab2d05326abb0afb460abd upstream.

When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.

Fix the problem by moving posix_acl_update_mode() out of
__ext4_set_acl() into ext4_set_acl(). That way the function will not be
called when inheriting ACLs which is what we want as it prevents SGID
bit clearing and the mode has been properly set by posix_acl_create()
anyway.

Fixes: 073931017b49d9458aa351605b43a7e34598caef
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jan Kara 
Reviewed-by: Andreas Gruenbacher 
Signed-off-by: Greg Kroah-Hartman